2 * linux/include/linux/mtd/bbm.h
4 * NAND family Bad Block Management (BBM) header file
5 * - Bad Block Table (BBT) implementation
7 * Copyright (c) 2005-2007 Samsung Electronics
8 * Kyungmin Park <kyungmin.park@samsung.com>
10 * Copyright (c) 2000-2005
11 * Thomas Gleixner <tglx@linuxtronix.de>
13 * This program is free software; you can redistribute it and/or modify
14 * it under the terms of the GNU General Public License as published by
15 * the Free Software Foundation; either version 2 of the License, or
16 * (at your option) any later version.
18 * This program is distributed in the hope that it will be useful,
19 * but WITHOUT ANY WARRANTY; without even the implied warranty of
20 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
21 * GNU General Public License for more details.
23 * You should have received a copy of the GNU General Public License
24 * along with this program; if not, write to the Free Software
25 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
28 #ifndef __LINUX_MTD_BBM_H
29 #define __LINUX_MTD_BBM_H
31 /* The maximum number of NAND chips in an array */
32 #ifndef CONFIG_SYS_NAND_MAX_CHIPS
33 #define CONFIG_SYS_NAND_MAX_CHIPS 1
37 * struct nand_bbt_descr - bad block table descriptor
38 * @param options options for this descriptor
39 * @param pages the page(s) where we find the bbt, used with
40 * option BBT_ABSPAGE when bbt is searched,
41 * then we store the found bbts pages here.
42 * Its an array and supports up to 8 chips now
43 * @param offs offset of the pattern in the oob area of the page
44 * @param veroffs offset of the bbt version counter in the oob are of the page
45 * @param version version read from the bbt page during scan
46 * @param len length of the pattern, if 0 no pattern check is performed
47 * @param maxblocks maximum number of blocks to search for a bbt. This number of
48 * blocks is reserved at the end of the device
49 * where the tables are written.
50 * @param reserved_block_code if non-0, this pattern denotes a reserved
51 * (rather than bad) block in the stored bbt
52 * @param pattern pattern to identify bad block table or factory marked
53 * good / bad blocks, can be NULL, if len = 0
55 * Descriptor for the bad block table marker and the descriptor for the
56 * pattern which identifies good and bad blocks. The assumption is made
57 * that the pattern and the version count are always located in the oob area
60 struct nand_bbt_descr {
62 int pages[CONFIG_SYS_NAND_MAX_CHIPS];
65 uint8_t version[CONFIG_SYS_NAND_MAX_CHIPS];
68 int reserved_block_code;
72 /* Options for the bad block table descriptors */
74 /* The number of bits used per block in the bbt on the device */
75 #define NAND_BBT_NRBITS_MSK 0x0000000F
76 #define NAND_BBT_1BIT 0x00000001
77 #define NAND_BBT_2BIT 0x00000002
78 #define NAND_BBT_4BIT 0x00000004
79 #define NAND_BBT_8BIT 0x00000008
80 /* The bad block table is in the last good block of the device */
81 #define NAND_BBT_LASTBLOCK 0x00000010
82 /* The bbt is at the given page, else we must scan for the bbt */
83 #define NAND_BBT_ABSPAGE 0x00000020
84 /* The bbt is at the given page, else we must scan for the bbt */
85 #define NAND_BBT_SEARCH 0x00000040
86 /* bbt is stored per chip on multichip devices */
87 #define NAND_BBT_PERCHIP 0x00000080
88 /* bbt has a version counter at offset veroffs */
89 #define NAND_BBT_VERSION 0x00000100
90 /* Create a bbt if none exists */
91 #define NAND_BBT_CREATE 0x00000200
92 /* Search good / bad pattern through all pages of a block */
93 #define NAND_BBT_SCANALLPAGES 0x00000400
94 /* Scan block empty during good / bad block scan */
95 #define NAND_BBT_SCANEMPTY 0x00000800
96 /* Write bbt if neccecary */
97 #define NAND_BBT_WRITE 0x00001000
98 /* Read and write back block contents when writing bbt */
99 #define NAND_BBT_SAVECONTENT 0x00002000
100 /* Search good / bad pattern on the first and the second page */
101 #define NAND_BBT_SCAN2NDPAGE 0x00004000
102 /* Search good / bad pattern on the last page of the eraseblock */
103 #define NAND_BBT_SCANLASTPAGE 0x00008000
104 /* Chip stores bad block marker on BOTH 1st and 6th bytes of OOB */
105 #define NAND_BBT_SCANBYTE1AND6 0x00100000
106 /* The nand_bbt_descr was created dynamicaly and must be freed */
107 #define NAND_BBT_DYNAMICSTRUCT 0x00200000
108 /* The bad block table does not OOB for marker */
109 #define NAND_BBT_NO_OOB 0x00400000
111 /* The maximum number of blocks to scan for a bbt */
112 #define NAND_BBT_SCAN_MAXBLOCKS 4
115 * Constants for oob configuration
117 #define ONENAND_BADBLOCK_POS 0
120 * Bad block scanning errors
122 #define ONENAND_BBT_READ_ERROR 1
123 #define ONENAND_BBT_READ_ECC_ERROR 2
124 #define ONENAND_BBT_READ_FATAL_ERROR 4
127 * struct bbt_info - [GENERIC] Bad Block Table data structure
128 * @param bbt_erase_shift [INTERN] number of address bits in a bbt entry
129 * @param badblockpos [INTERN] position of the bad block marker in the oob area
130 * @param bbt [INTERN] bad block table pointer
131 * @param badblock_pattern [REPLACEABLE] bad block scan pattern used for initial bad block scan
132 * @param priv [OPTIONAL] pointer to private bbm date
141 int (*isbad_bbt) (struct mtd_info * mtd, loff_t ofs, int allowbbt);
143 /* TODO Add more NAND specific fileds */
144 struct nand_bbt_descr *badblock_pattern;
149 /* OneNAND BBT interface */
150 extern int onenand_scan_bbt (struct mtd_info *mtd, struct nand_bbt_descr *bd);
151 extern int onenand_default_bbt (struct mtd_info *mtd);
153 #endif /* __LINUX_MTD_BBM_H */